Composite components such as airframes component, including but not limited to aircraft skins, spars, ribs, frames, longerons, stringers and stiffeners, can be fabricated from flat composite ply layups. The composite airframe components can be provided with complex cross-sectional shapes, such as, e.g., an “L”, “U”, “Onion”, “hat”, “I”, “T”, “J”, “Z” or the like cross-sectional shapes, depending on, at least the type and amount of load the composite airframe component is designed to carry. The cross sectional shapes are configured to stiffen the composite airframe components where the composite airframe components are folded to form portions of the cross section but leave voids or cavities where the folds meet the other elements of the composite section. For example, the composite airframe components can be fabricated by abutting legs of two composite structural members so as to form groove or channel at their junction where the groove is then filled with a composite material. In one aspect, the composite material is placed within the groove of the composite airframe component where voids are left between the composite material and surface(s) of the two composite structural members. In other aspects, extrusion of a composite material causes the surface of the extruded composite material to tear or exhibit other poor surface and edge qualities. In still other aspects, a shape of the extruded composite material may change or twist after the composite material is extruded.